Skewer Kite Posts—Rokkaku

(Bamboo BBQ Skewer Spars)

It's an archive of sorts, although there are no dates and times. Kite flying is timeless, don't you agree?

I trust there is plenty in here to educate, inform, and often entertain!

These short flight reports once appeared as posts in the site-blog page, although that page is no longer present on this site. Below, the latest posts come first. Just scroll down and stop at any heading that appeals :-)

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2-Skewer Rokkaku Kite

Rok Over the Roof

It had been a stinking hot couple of days. In fact, it was the hottest start to autumn since records began.

Early yesterday, fresh gusty winds had whipped around the yard while we had the house closed up to keep the cool air in. However, with the sun nearing the horizon, things had calmed down a lot. It was time to venture out with a light-wind kite!

Skewer Rok Strains

It was the 2-Skewer Rokkaku kite, to be precise. A cool breeze was gusting well into the moderate range.

On this occasion the flying field was a small open space next to a BMX track. Have a guess who got a bike for Christmas (Aren!) ... anyway ...

Initially the bright-orange rokkaku stayed up on just several meters of line, while anchored under the carry bag. A large bushy tree just upwind made things interesting by blocking much of the breeze. But the kite caught enough air, and often enough, to remain in flight.

Moving the bag and winder cross wind for several meters, I let the kite up on perhaps 20 meters (60 feet) of line for a while. Here, out of the lee of the tree, the breeze was more constant. Still, moderate strength gusts powered through every half a minute or so.

The small rok was at its limits during the peak of some gusts, which curved all the spars in a pronounced way. It was a good demonstration of how sheer wind speed can lower line angle due to drag forces predominating over the lift being generated. The rokkaku was forced, tail first, down to just 20 or 30 degrees of line angle at these times. Remember, this is a kite that likes to go right overhead from time to time. In fact, it still did that today—during lulls!

After this, some more line was let out which allowed the kite to soar around several tree-heights above the dusty ground. Various birds noticed and a small flock flew past just to take a look. And then a lone galah buzzed me as I tried to capture it on video!

Shortly after this, when winding in line to bring the kite down, there was a brief gust to 26 kph. The average had been sitting around 17 kph, according to the wind meter.

It had been a while since the 2-Skewer Rokkaku had been tested in such a stiff breeze, but it came through with no damage. Bamboo is wonderful stuff!

Rok in Rough Air

Once again the boy was keen to take out his quadcopter and once again I took out the 2-Skewer Rokkaku kite.

This time there was no shortage of wind. We were flying just downwind of a small stand of trees which had been planted as saplings some years before. Tsk tsk people keep eroding our inland kite-flying spaces don't they. Schools, councils, they're all at it ;-)

Even well above tree height, the little rok bounced around in active air. Sometimes it pulled strongly, at other times it would suddenly fall flat on its face and drift downward. A prolonged surge right overhead confirmed that the mayhem was thermal induced. Perhaps that small stand of trees was helping to kick off parcels of rising air so close to where we were flying. The rok was only on 100 feet or so of 20-pound Dacron.

I took a few videos which will probably suffer a bit from having a completely blue background. A few clouds would have really highlighted the motion of the kite!

Somewhat to my surprise, Aren volunteered to fly the rok for a while, and he also helped to bring it down. I guess a flat battery in the quadcopter helped. Boredom sets in quickly with 12-year-olds.

There are a few cooler and cloudier spring days coming now, so it was good to get the rok (and the boy!) out in the sun for awhile.

Rokking in Nearly Zero Wind

Last weekend my boy was keen to take out his quadcopter, so I tagged along with the 2-Skewer Rokkaku kite.

We chose a grassy patch that attracts the occasional parent(s) with young children (of the human or furry variety). However, with the play equipment situated near one end it was quite a practical location at which to fly.

Despite the little rok's great light-wind performance, there really was very little up there. Tows on a long line would find the occasional puff that would suspend the kite for a few seconds. That was before the inevitable downwards drift resumed. When the 20-pound Dacron went very slack, the kite was prone to enter a shallow nosedive, sail edges rippling as it went. A few quick gathers of the line would then raise the nose and halt the dive. But then further pulling in was needed to keep the kite in a flying attitude—but coming down all the while.

So, there were a number flights of that nature.

Some flights utilized almost the whole length of the available space, but all to no avail. If anything, the breeze had died even further after we had been there half an hour or so!

Launches were done by simply dragging the kite off the grass, on full line length. With the kite off-center, the dihedral angle would let the sail catch some air and cause the kite to lift off nearly parallel to the ground. After that, the natural stability of the rok would quickly straighten it up into a vertical climb.

Oh well, it turned out to be a light-wind-handling skill-building session. However, for Aren's toy-grade quadcopter, conditions couldn't have been better.

The Rok, the Pelican, and the Ice Crystals

Another dusted-off 2-Skewer kite took to the air yesterday afternoon.

The air was almost still at times, as moderately strong thermals drifted through every few minutes. My son Aren (who insisted I mention that he's almost 12 now) took advantage of the relatively light winds down low with his quadcopter. Meanwhile, I ruled the upper altitudes with the 2-Skewer Rokkaku.

Initially, the lightweight rok had trouble staying up with the breeze gusting to around the middle of the light range. However, working those modest gusts eventually led to getting more line out, and the kite went up to over 150 feet off the grass—or should I say weeds, at this particular field. It was sheer flying pleasure after that.

The small bright-orange rok soared effortlessly around at steep line angles. The sides of the sail outline would curve inward from time to time in response to higher wind speeds.

Around this time I noticed a subtle rainbow surrounding the sun. This phenomenon is caused by sunlight refracting though high-altitude ice crystals. To top it off, there was also a high-altitude pelican, soaring nonchalantly within the rainbow. The distant wing shape was tiny but unmistakable.

The prevailing breeze was very light but the thermals were certainly tugging at the kite. During one video, I panned from a car traveling along next to the field to where the flying line started its upward arc. From there I panned up and up and up ... crikey—the kite's gone vertical! There it was, on 60 meters (200 feet) of 20-pound Dacron, pulling firmly but unsure which way was up.

So, it was not the most ordinary of outings.

Redesigned 2-Skewer Rokkaku Rockets Up

I say "redesigned" but this rok is almost identical to the original one, to look at. The main reason for making another one was to update the How To ... instructions on the website. The new instructions are significantly simpler than the old ones and provide more foolproof help with doing the bridle lines.

This morning appeared to be a good opportunity to fly this rok before winds strengthen over the next few days. Even so, the 2-Skewer Barn Door was also taken along, as a back up!

To my horror, the rokkaku initially just spun around, completely unstable. Ooops, this design has already been published! But then, with a little adjustment of the bridle, I managed to get the kite a few meters up and it settled down.

Without the bow line of the original design, this rok was behaving like a fighter kite when under very light wind pressure. Just a few extra kph of airflow had the effect of putting a little extra dihedral in the lower horizontal spars. There is something to be said for 3-leg bridles on rokkakus! Then the magic started to happen.

The breeze was cold and gusty down low but relatively smooth higher up. The weather was sunny with clouds here and there, but convection seemed fairly mild. The little 2-Skewer Rokkaku flew smoothly and high with no hint of instability. A few minutes were spent on 30 meters (100 feet) of line. Then 60 meters (200 feet) and finally 90 meters (300 feet) of line were let out.

Way up high on a tight 20-pound line, the bright-orange rokkaku behaved itself impeccably, showing off great performance, stability, and wind range! Even as the wind speed started to edge higher around 20 kph, the kite just distorted evenly and settled out a little lower. Not wanting to push it any further, I started winding in.

Within 40 feet or so of the ground, the rok started spinning this way and that in the slower rougher air. This isn't the easiest kite to bring right in to your hand!

The wind meter registered an average of 3.1 kph near the ground with gusts to 11.5 kph. The very firm pull on the line told a different story about the conditions at 250 feet above the grass. 

2-Skewer Rokkaku Handling Gusts

This was another brief but enjoyable session while shopping was taking place at another location ;-) The 2-Skewer Rokkaku was pulled out this time, since the breeze didn't seem excessive in strength. After flying the kite around on a short line near one edge of a school oval, it was decided to move further out. The air was just too rough, due to some rather tall and leafy trees upwind!

With perhaps 15 or 20 meters (60 feet) of line out and anchored to my shoe, the 60 cm (48 in.) span kite flew all over the place. The breeze was gusty and pushing over 25 kph at times—quite a test for the rok which does best in light winds. But it was coping.

Due to the warm weather there was a bit of trouble with old bits of electrical tape coming off at the spar tips, but I just squeezed them back on and kept flying. The rokkaku kite, in traditional dimensions, is an amazingly stable tailless kite. It will stay up all day on a long line in light winds. Or it will do it in moderate winds, if built a little heavier.

When I checked the wind meter, which had been parked on a log fence, it had registered an average of 11 kph gusting to 24 kph. This is pretty ideal for most kites, if a little on the strong side for most of my light-wind designs!

Big Sled, Little Rok

There was a window of only half an hour or so to get out and fly something in the late afternoon. Aren (6 years old) actually volunteered to fly too. Although he features on a number of pages on this site, he hasn't been a keen kiter in recent times. His mum's smart phone has its attractions you see! Anyway.

Out at the school reserve, the southerly was fairly unobstructed; there were no tall trees on the upwind side of the field. This was good for the Dowel Sled, which is very picky about the air it flies in. Aren had the MBK 2-Skewer Rokkaku on a 20-pound line, while I flew the sled on the 50-pound line. 

Aren was soon complaining about the line pull on the rok. Although smooth, the breeze was gusting up close to moderate strength at times, up around 100 feet off the grass. This was pushing the rok fairly hard. Mind you, Aren has ample strength now to handle a kite of this size.

Meanwhile, the sled was having mixed success. Just like the redesigned 2-Skewer Sled some days ago, the wind strength was just a little too much for it while it was at its highest line angles. The bamboo skewer taped down the centerline was doing a great job preventing the leading edge from collapsing, the rest of the time.

Near the ground, the wind meter recorded an average of 4.3 kph and a maximum gust of 12.2 kph. The wind was not too turbulent perhaps, but it sure was gusty! 

Wet Wok Wallows Then Wises Willingly

A bit of Elmer J. Fudd there. Anyway, in clearer English—the 2-Skewer Rokkaku kite got a bit damp on the grass but rose willingly enough in the end. Puffs of 10 kph air were traversing the reserve every few minutes. In between, it was hard for even this light-wind design to stay up long enough for a short video.

Eventually, with quite a bit more line out, the small rokkaku rose high and dried off nicely in the bright sunshine. Hovering a short distance from the tree it was anchored to, the kite flew around sedately at a steep line angle. As usual, particularly in this location, the breeze aloft was much more consistent than at head height.

Rok Rose Reluctantly

... and then descended back to the wet clover, after failing to stay up on almost 60 meters (200 feet) of damp 20-pound Dacron line. It was worth a try since this kite will stay up on almost nothing. The only trouble was, there was slightly less than "almost nothing" by the time we had walked up to the vacant block!

Palm fronds, normally a good indicator of wind speeds under 5 kph, were barely moving. This wasn't a good sign at all. And it seems that light conditions in the very late afternoon usually just get lighter still. Some call it "glassing off," which is probably a reference to the appearance of water in nil wind—one giant mirror!

Initially, I had launched on shorter lengths, only to find the line getting shorter and shorter as I took the necessary action to keep the kite flying. Sometimes, I would launch directly off a clump of clover and at other times Aren would point the nose up just prior to launching. When left to its own devices, the kite would rock rapidly as one side then the other would stop flying in the insufficient airflow. All the while, the kite was losing height.

The little rok also spent a good amount of time just gliding around on a slack line. Perhaps the dampness of the line wasn't helping, the extra weight pulling the kite's nose down more than usual while flat on its face.

Anyway, I had a bit of fun doing saves just a meter or so from the ground. It was a bit like handling a fighter kite, requiring a firm pull just when the nose swung through vertical.

See, you can still get some enjoyment even when there is—as bystanders are fond of saying—"not enough wind"!

High Tow, No Go

Well, it wasn't a complete flop with the 2-Skewer Rokkaku, but moving air was hard to find.

The winter solstice is approaching down here, meaning the days are short. Out at a nearby park around 5 pm, the skies had started to darken. Treetop leaves were barely moving, which wasn't a good sign. A better sign was a clump of low cloud scudding past at around 2000 feet. Too bad it's illegal to fly up there with a kite!

After a couple of tows to about 100 feet off the grass, it was clear that even a great little light-wind kite like the 2-Skewer Rokkaku just wasn't going to stay up for even two minutes. But then things got interesting.

As a final attempt, and fully expecting a floating-leaf-like descent to ground, I did a tow-up using almost the full diagonal length of the field. Sure enough, after topping out at over 200 feet altitude, the rok started to descend in floating-leaf fashion. However, after losing perhaps 50 feet, the descent halted and the kite hung motionless for half a minute or so.

The field has a gentle downward slope on one side and as I moved back and took some line in, the kite was approaching the slope. Could it be that some very subtle slope lift was keeping the kite up? Possibly! I used to fly slope lift in sailplanes in younger days. Anyway, it eventually became necessary to keep hauling line in and the bright-orange rok ended up on the damp grass a minute or two later.

So, there was some semi-satisfying flying after all!

 

 

 

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